The present invention relates to an ice cream machine, and to a dasher for use in an ice cream machine. The invention additionally relates to a method of making ice cream using the machine within the freezer compartment of a refrigerator.
Devices for making ice cream in the freezer compartment of a refrigerator are known. In one such apparatus, the ingredients for making ice cream are chilled for at least 2 hours and then placed in a receptacle in the freezer of a refrigerator. A power unit, which must be connected to an external power supply by means of an electric cord extending through the freezer door, is placed over the receptacle, and a dasher is positioned in the receptacle for stirring the mixture. The dasher is rotated by the power unit, and contacts the bottom and walls of the receptacle to scrape them clean of the frozen mixture. Accordingly, the power unit for rotating the dasher must be of relatively high capacity to drive the dasher as the mixture freezes. When the ice cream has sufficiently frozen, the dasher slows down and the power unit is eventually shut off. See for example U.S. Pat. No. 2,962,267, wherein a high speed agitator is additionally employed.
In another ice cream machine, the receptacle is toroidal in shape and a power unit is located within the central aperture. The drive shaft of the power unit extends upwardly to a cross arm. At each end of the crossarm, a paddle extends downwardly into the ingredients to be mixed. Again, the device is placed inside the freezer of a refrigerator and an electric cord must pass through the freezer door to be plugged into the nearest electrical outlet. The paddles are rotated in the unfrozen mixture until the mix has attained the proper consistency, usually about sixty minutes, and the paddles then are lifted automatically from the mixture. The mixture is left in the freezer compartment for an additional 1 to 2 hours to obtain the desired hardness.
The main deficiency of each of these machines is that they must be plugged into an external power supply by an electric cord which must pass through the freezer door. The cord is liable to be damaged by the door as it is opened and closed. If the cord is improperly positioned, the door may be left ajar and the other freezer contents will become unfrozen. Some potential consumers are reluctant to place a machine in their refrigerator wherein the cord extends through the door out of fear of an electric shock. A further problem is that as the dasher is rotated at a relatively high speed in order to agitate the mixture, and since the dasher scrapes the frozen mixture from the wall and bottom of the receptacle, it is necessary to use a high power electric motor to drive the dasher, particularly as the mixture begins to freeze. It is impractical to supply current to such high power electric motor from a battery.